Washing machine and method for operating a washing machine

ABSTRACT

A washing machine has a housing and a drum unit with a cup-like tub and a cylindrical drum, which is rotatably mounted in the tub about its cylinder axis. The tub and the drum open out at the end face in a loading and unloading opening of the drum unit. The drum unit can be tilted about a tilt axis that is perpendicular to the cylinder axis, between a loading and unloading position, wherein the loading and unloading opening points obliquely upward, and a wash position for a wash cycle. The housing has a displaceable front wall coupled with the drum unit. A door closes a breakthrough in the front wall that always covers the loading and unloading opening of the drum unit.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority, under 35 U.S.C. §119, of German patent application DE 10 2014 226 318.2, filed Dec. 17, 2014; the prior application is herewith incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION Field of the Invention

The invention relates to a washing machine, in particular a washing machine for domestic use. In addition, the invention relates to a method for operating such a machine.

Washing machines usually comprise a cylindrical drum which is mounted in a tub that in the majority of cases is realized in a cup-like manner so as to be rotatable about its drum axis. Items of laundry to be washed are arranged in the drum when the washing machine is in operation. The tub, in this case, surrounds the drum up to a loading and unloading opening (arranged in the majority of cases on an end face of the drum). The loading and unloading opening is closed by means a door when the washing machine is in operation.

A wash program sequence with, in the majority of cases, several program steps (also designated as “cycles”) is executed by the washing machine in operation. Thus, in one program step designated as a wash cycle, the tub and the drum are partially flooded with the so-called “wash solution” or “detergent solution,” a mixture of water and one or several additives (detergent, fabric softener and the like). The drum rotates in the wash cycle in the majority of cases at a slower speed, frequently with multiple reversal of the direction of rotation such that the items of laundry are moved and wetted sufficiently by the washing liquid. On account of inwardly projecting ribs of the drum, the items of laundry, at the same time, are also lifted out of the washing liquid until they drop back due to gravity and at the same time change the position in which they are held (i.e. tangles undone and/or folds changed). As a result, the items of laundry are moved in a particularly vigorous manner and impurities are efficiently washed out. In the majority of cases, the wash cycle is followed by the washing liquid being replaced by clear water (also designated as “rinse cycle”) in order to wash the detergent residues out of the items of laundry and consequently (after drying) to avoid detergent stains. In the rinse cycle, the drum rotates frequently in a similar manner as in the wash cycle. A spin cycle, in which the drum rotates at a higher speed, is then regularly provided, the water being expelled out of the items of laundry as a result of centrifugal forces.

In the case of conventional washing machines—used chiefly in the European market—the tub and the drum are arranged with a horizontally aligned drum axis. The drum, in this case, mostly comprises a loading and unloading opening arranged at the end face (so-called “front loader” washing machine) such that a person who loads or unloads the drum often has to kneel in front of the washing machine. In addition, where the drum is aligned in such a manner, in the spin cycle imbalances and consequently also vibrations of the drum frequently occur transversally and longitudinally with respect to the drum axis caused by uneven distribution of the items of laundry along the inside wall of the drum. The imbalances and vibrations have to be absorbed by providing the drum and the tub with a sufficiently flexible bearing arrangement and damping so that they are not transmitted to an (exterior) housing which surrounds the tub and the drum. Otherwise, the entire washing machine is likely to wander.

Widespread in the American and Asiatic markets, in contrast, are washing machines where the drum axis is perpendicular and where the loading and unloading is effected from the top (often also designated as “top loader” washing machines). The top loader washing machines are advantageous as regards the vibrations in the spin cycle as in the majority of cases fewer vibrations occur in the direction of the drum axis compared to front loader washing machines. However, a comparatively higher water level has to be set in the tub in the wash cycle so that the items of laundry are able to float and to be moved at all. In addition, a so-called impeller, a plate arranged on the bottom end face of the drum with blades for transmitting the rotation of the drum to the items of laundry (and to the washing liquid), or an agitator are frequently arranged inside the drum. The latter is an axially central rod with blades which rotates with the drum and regularly strikes the items of laundry floating in the washing liquid and thus moves them thoroughly. Consequently, compared to front loader washing machines, these types of top loader washing machines have an increased water consumption and frequently also a mechanical load on the items of laundry is greater. In addition, small persons find unloading the top loader washing machine difficult in the majority of cases as they are often not able to reach the bottom of the drum.

SUMMARY OF THE INVENTION

It is accordingly an object of the invention to provide a washing machine and method of operating a washing machine which overcomes the above-mentioned and other disadvantages of the heretofore-known devices and methods of this general type and which, simply, provides for an improved washing machine.

With the foregoing and other objects in view there is provided, in accordance with the invention, a washing machine, comprising:

a housing;

a drum unit mounted in said housing, said drum unit including a cup-shaped tub and a cylindrical drum with a cylinder axis, wherein said drum is rotatably mounted in said tub about said cylinder axis;

said tub and said drum opening out at an end face in a loading and unloading opening of said drum unit;

said drum unit being disposed to assume a loading and unloading position wherein said loading and unloading opening points obliquely upward;

said drum unit being mounted in said housing for tilting in a wash cycle relative to the loading and unloading position about a tilt axis that extends perpendicular to said cylinder axis of said drum, into a wash position; and

said housing having a displaceable front wall coupled with said drum unit, said front wall being formed with a breakthrough that covers said loading and unloading opening of said drum unit, and a door articulated on said front wall for closing both said breakthrough and said loading and unloading opening.

In other words, the washing machine according to the invention includes a housing and a drum unit which is mounted in the housing. The drum unit, in this case, comprises a cup-like tub and a cylindrical (wash) drum, wherein the drum is mounted in the tub so as to be rotatable about its cylinder axis (hereafter referred to as drum axis). The drum unit additionally comprises a loading and unloading opening into which the tub and the drum open out in each case at the end face. This means that the tub and the drum in each case comprise at the end face a (tub or drum) opening which together form the loading and unloading opening of the drum unit. According to the invention, the drum unit is arranged in a loading and unloading position in such a manner that its loading and unloading opening points obliquely upward. This means that the drum axis is aligned obliquely (with respect to the horizontal) in the loading and unloading position. In a wash cycle, in contrast, the drum unit is tilted in the housing into a wash position in relation to the loading and unloading position. The tilt axis about which the drum unit is tilted, in this case, is perpendicular to the drum axis. In addition, the tilt axis is preferably located in a horizontal plane such that the tilt movement of the drum unit extends in a vertical plane.

The drum is hinged in the tub so as to be rotatable about its drum axis, but is otherwise preferably non-movable. When the washing machine is operating—i e. during a cycle of a washing program sequence—the drum therefore rotates in the tub (which is supported in the housing so as to be non-rotatable). Movements in other directions, that is to say in particular the tilting movements between the wash position and the loading and unloading position, are effected, in contrast, in one unit with the tub.

The tub serves in particular as a receptacle for the so-called washing liquid or also for clear water which is used in the wash cycle or in a rinse cycle to wash or rinse the items of laundry. The drum itself is preferably developed so as to be liquid-permeable by means of a plurality of wall breakthroughs such that, in operation, with the drum rotating, the washing liquid (or the water) also passes into the interior of the drum and consequently the items of laundry are moved in the liquid “standing” in the tub.

As regards the method, when the washing machine is operating,—at the launch of a wash program sequence (preferably selected in a user-specific manner)—the drum unit is therefore tipped from the loading and unloading position into the wash position. In an expedient manner, at the end of the entire wash program sequence the drum unit is tipped (back) into the loading and unloading position again—and the wash program sequence then ends.

As a result of the drum unit being aligned obliquely in the loading and unloading position, the handling of the washing machine is made easier for a person utilizing the washing machine (the user). When loading or when unloading the drum, the user needs namely (as in the case of a front loader washing machine) neither to kneel or to bend in front of the machine nor does the user, when unloading, as in the case of a top loader washing machine, need to bend over the machine in order to be able to reach items of laundry that are located at the bottom of the drum. In the loading and unloading position, the drum unit is preferably aligned with the drum axis between approximately 30 and 70 degrees with respect to the horizontal, in particular at an angle of approximately 45 degrees. Consequently, both large and small persons are able to look into the drum in a simple manner and reach deeply into the drum in such a manner that they reach items of laundry that are located on the drum bottom.

In a preferred realization, in the wash cycle the drum unit is tilted in such a manner in the wash position that the drum axis is aligned in a horizontal manner. The wash position is also designated below as the horizontal position of the drum unit.

In a particularly expedient realization of the washing machine, when operating it runs through a further operating state after the wash cycle which is designated as a spin cycle. In the spin cycle, the drum unit is arranged in a spin position and in this case is preferably tilted in relation to the loading and unloading position and the wash position in such a manner that the drum axis is aligned in a vertical manner. The spin position of the drum unit is also designated below as the vertical position. The wash cycle and/or the rinse cycle are executed in particular in the wash position. In contrast, (preferably only) the spin cycle is executed in the spin position. In the spin cycle the drum rotates at a high speed in order to drive the washing liquid and/or the water at least in part out of the items of laundry as a result of the centrifugal force. The advantage in this connection is that with the drum unit in the vertical position (that is also the drum), the effect of the vibrations of the drum brought about by imbalance in the spin cycle is chiefly radially to the drum axis. Consequently, vibration damping for the drum unit (by means of which the drum is also damped on account of the bearing arrangement thereof in the tub) is able to be developed in a comparatively simple and cost-efficient manner. In addition, the water consumption in the wash and/or rinse cycle is comparatively low with the drum axis in the horizontal position.

As regards the method, after the end of the wash cycle (and/or the rinse cycle), the drum unit is consequently tipped, in particular automatically, from the wash position into the spin position for the connecting spin cycle—i.e. into the vertical position. After the end of the spin cycle, the drum unit is tipped back again into the loading and unloading position.

In an alternative implementatoin, the drum unit is tipped into the vertical position both in the wash cycle and in the spin cycle. In other words, the wash and rinse position correspond to each other in the realization. In this case, the drum unit is preferably only tippable between the loading and unloading position and the vertical position.

In an implementation which is inventive per se, the housing comprises a stationary front wall with a breakthrough which covers the loading and unloading opening when the opening is arranged in the loading and unloading position. The front wall is preferably arched in arcuate manner and in this case is adjusted in particular to the tilt radius of the drum unit. The breakthrough is preferably realized in a circular manner with a radius which corresponds to the radius of the drum or is slightly larger (i.e. by a few centimeters).

Within the framework of the invention, it is certainly conceivable for the breakthrough of the (stationary) front wall to remain free (that is open). In order, however, to achieve a particularly high level of operational reliability in particular for a home environment, in an advantageous realization the housing comprises a flat sliding door, by means of which the breakthrough when the washing machine is operating (i.e. with the drum and/or drum unit moving) is closed in an access-secure manner. The sliding door, in this case, is guided on the outside so as to slide with respect to the front wall. In a preferred variant, the sliding door is set up for manual displacement between its open position (opening the breakthrough) and its closed position (covering the breakthrough). In an alternative variant, the sliding door is coupled with a door drive and is consequently adjusted automatically between the open position and the closed position. In addition, the washing machine preferably includes in both variants a closing signal generator which is actuated (triggered) by the sliding door in the closed position thereof such that a wash program sequence is only able to be started when the sliding door is closed. As an option, the washing machine also includes a door lock for the sliding door which is set up to keep the sliding door in its closed position during a wash program sequence in order to prevent access to the interior of the housing.

In an expedient realization, the sliding door is set up and realized for the purpose of being displaced downward from the closed position into the open. This means that the sliding door is displaced in the open position in the direction of the bottom surface of the housing.

In a further preferred implementation, the sliding door is developed at least in part in a transparent manner such that even when the sliding door is closed, it is possible to look into the housing and onto the drum unit. The sliding door, in this case, preferably comprises a windowpane which is inserted into a window of the sliding door. As an alternative to this, the sliding door is produced entirely of transparent material (e.g. of glass, in particular however of a plastics material), as an option an (in particular circumferential, window frame-like) edge region of the sliding door being developed in an opaque manner (e.g. painted or back-injected).

In an advantageous realization, the washing machine comprises a bellows which is arranged between the drum unit and the front wall. The bellows is set up in particular for the purpose of closing the spacing between the front wall and the drum unit in a liquid-tight manner—when the drum unit is arranged in the loading and unloading position. To this end, the bellows is preferably realized at least over a part region of its length so as to be in particular actively, i.e. automatically, length-adjustable. In the development, the bellows (comparable to a passenger bridge at an airport) is hinged non-movably to the front wall (or to the drum unit) and is only “docked” on the drum unit (or on the front wall) in the extended state with the drum unit arranged in the loading and unloading position (that is extended and in liquid-proof contact with the drum unit or the front wall). During the operation of the washing machine (that is during a wash, rinse or a spin cycle) the bellows, in contrast, is retracted in a rest position (its length shortened), such that the drum unit is able to move freely in relation to the front wall. In a particularly preferred manner, the bellows is fastened on the front wall and is actively extendable and retractable in the direction of the drum unit. The bellows prevents in a particularly effective manner, when loading and unloading the drum, items of laundry and/or liquid from being able to pass into the gap between the front wall and the drum unit and consequently into the interior of the housing.

In an expedient further development, the above-described bellows is coupled with an outlet line. This latter is realized in such a manner that liquid dripping onto the bellows is directed directly or indirectly out of the housing of the washing machine. In a simple variant, the outlet line is simply formed by a tube or hose line which is guided out of the housing and in an approved installation state of the washing machine (for example in a room serving as a laundry room) leads into a building-side outlet. In an expedient variant, the outlet line is however coupled with a wastewater system of the washing machine such that, where applicable, liquid accumulating on the bellows is pumped together with the washing liquid and/or the water from the rise cycle out of the washing machine.

In an expedient realization, the washing machine includes a closure, which is designated as a drum cover, for the loading and unloading opening of the drum unit. The drum cover is fitted onto the drum unit in such a manner during the operation of the washing machine that the loading and unloading opening is closed in a liquid-tight manner. In an advantageous manner, the drum cover is developed in this case in such manner that a gap, which is formed for free rotation of the drum in the tub between the edges of the end-face openings of the drum and of the tub, is covered. In particular, the drum cover, in this case, is provided with a projection which points to the drum and in the closed position of the drum cover projects in part into the drum and consequently covers the gap. As a result, items of laundry are prevented in a simple and effective manner from passing into the gap and getting damaged or being “lost” in the space between the tub and the drum when the washing machine is operating. In addition, the drum prevents the washing liquid or the water from leaking out of the tub when the drum unit is arranged in the horizontal position. For the case where a horizontal position is not provided for the drum unit, the optional realization does not include the drum cover.

In an expedient manner, the drum cover is hinged on the drum unit so as to be pivotable. In particular, the drum cover, in this case, is set up for the purpose of being manually operated—at least manually closed. In an optional and preferred realization, however, an automatically opening lock for the drum cover is arranged on the drum unit. The lock is set up in particular for the purpose of opening the drum cover automatically such that the drum cover—in particular under the action of a damped spring mechanism—pivots up into its open position once the sliding door has been opened as a reaction to the triggering of a control element (e.g. to the actuating of a limit switch by the sliding door in its open position or to a user pressing a button).

In order to enable a particularly high level of operating comfort, the drum cover, in an alternative, advantageous realization, is completely separable from the drum unit. The drum cover, in this connection, is fully removed (mechanically separated) from the drum unit in the loading and unloading position and is preferably arranged in a receiving means which is arranged inside the housing such that the drum unit is able to be moved independently of the drum cover. In the realization, the washing machine preferably includes a device which is designated as a “park device” for removing and fitting the drum cover from the or onto the drum as well as for arranging the drum cover in the receiving means. In a preferred manner, in this connection, the fitting and the removing of the drum cover is effected with the drum unit in the vertical position. In an optional realization variant, the park device is, for example, a gripping arm, by means of which the drum cover is lifted and guided into a park position. In the case, the gripping arm preferably also at the same time forms the receiving means which holds the drum cover in the park position. In an alternative realization variant, the park device includes, for example, a linkage guide arranged on the inside of the housing, along which the drum cover (preferably also with the vertical drum unit) is displaced into the park position and in this case is deposited in particular onto at least one stop (forming the receiving means). The realization of the washing machine with the fully removable drum cover provides—in particular in combination with the sliding door for closing the front wall—the advantage that when loading or unloading the washing machine no door (or no cover) protrudes beyond the outside contour of the housing and consequently projects into the movement range of the user. In addition, the user only needs to operate one door, namely the sliding door.

As regards the method, in the case of the removable drum cover the drum unit is tipped in to the vertical position at the launch of the wash program and the drum cover is fitted onto the drum unit and preferably locked. The wash cycle is then started and the drum unit where applicable tilted into the horizontal position. Finally, (i.e. where applicable after carrying out the spin), with the drum unit in the vertical position, the drum cover is removed from the drum unit and the drum unit is tilted into the loading and unloading position again.

In an expedient further development of the afore-described realization of the drum unit with a pivotable or removable drum cover, the loading and unloading opening is realized substantially (i.e. approximately) as a segment of a circle with a central angle in excess of 180 degrees. The loading and unloading opening, in this connection, is preferably realized as a segment of an approximately three-quarter circle. A “segment of a circle” is to be understood in this connection as the surface defined by an arc of a circle and a chord of a circle. The opening of the drum itself is expediently formed in the further development in the manner of a circle. The tub, in contrast, comprises on its end face an end wall portion which is in the manner of a segment of a circle—complementary to the segment of a circle of the loading and unloading opening (in particular corresponding approximately to a quarter circle)—, by means of which the drum opening is partially covered in the final assembly state. This is particularly advantageous as no full circular opening is necessary for loading and unloading the drum. In addition, on account of the reduced loading and unloading opening (in relation to the diameter of the drum), it is also possible in an advantageous manner to reduce the drum cover. As a result, handling thereof, in particular with regard to the afore-described automatic park device, is simplified.

In particular, for the case where the sliding door is realized at least in part in a transparent manner, in an expedient realization the washing machine comprises an indicator device for the operating state (wash cycle, spin cycle etc.) of the washing machine. The indicator device, in this case, is realized in such a manner that the indicator (showing the operating state) is visible to a user from the outside of the housing through the transparent part of the sliding door (e.g. the windowpane thereof). In a simple realization, the indicator device is formed by (indicator) plates (preferably with fixedly predefined text) fastened on the drum unit (for example on the lateral surface of the tub), which, on account of the tilting of the drum unit into the respective operating position, are pivoted into the field of vision of the user through the sliding door. In an alternative realization, the indicator device includes a display which is coupled, in particular, with the transparent part of the sliding door or is set up for the purpose of projecting the respective information onto the sliding door.

According to the invention, the front wall is developed so as to be displaceable and is coupled with the drum unit such that when the drum unit is tilted between the, or where applicable each, operating position and the loading and unloading position, the front wall is entrained in a corresponding manner. In the realization the front wall also comprises a breakthrough which, on account of the coupling with the drum unit, always covers (i.e. in every position) the loading and unloading opening of the drum unit. In addition, in the realization, the washing machine includes (simply) one (loading) door for closing both the breakthrough and the loading and unloading opening. The door, in this case, is preferably realized in the manner of a conventional (front loader) washing machine door such that, in the closed state, the door covers the gap between the front wall and the drum unit as well as the separating gap between the tub and the drum. The gap between the front wall and the drum unit, in this case, is preferably closed in a liquid-tight manner (e.g. by means of a bellows) such that, in particular with the loading door open, no liquid is able to pass into the interior of the housing. The front wall, in this case, is realized in particular as a (louvre-like) blind which is wound in each case at both its ends on a roller. As an alternative to this, the front wall is realized in a rigid manner per se (i.e. in the manner of a plate) and is displaceably guided along a substantially circular path on the housing.

In a further expedient realization, the displaceable front wall is formed by several interconnected lamellae. The lamellae preferably extend transversely with respect to the direction of displacement of the front wall (i.e. transversely with respect to the tilt direction of the drum unit). The lamellae are additionally set up in particular for the purpose, when the drum unit is tilted, of moving one above another in a “scale-like” manner (to form a type of stack) at the top or bottom end of the front wall. The individual lamellae are removed from the stack located at the corresponding other end of the front wall.

In a preferred realization, the bellows is connected to the drum unit and the front wall in every position of the drum unit (i.e. constantly).

Irrespective of the development of its front wall, the washing machine includes, in a further expedient realization, an automatic dosing unit for additives for mixing the respective washing liquid. The additives are, in particular, detergents and/or fabric softeners or the like. The dosing unit preferably comprises one or several storage containers for receiving a quantity of (powdery and/or liquid) additives sufficient for one or several wash program sequences. A necessary quantity of the respective additive is automatically dosed from the storage container or, where applicable, from the several storage containers during the wash program sequence (for example by means of a feed screw, a dosing scale or the like). Consequently, the user of the washing machine does not need to dose the respective additives separately and independently for each wash program sequence. For the case where the washing machine comprises the fixed front wall, the dosing unit is arranged, in particular, in a base region of the housing.

Nevertheless, to enable user-specific dosing of additives—for example in dependence on the laundry to be washed, the washing machine includes in an expedient manner, in addition to or as an alternative to the afore-described dosing unit, a receiving means and dispensing device for such additives which are to be added in a user-specific manner (e.g. for special tablets or powder).

In a preferred further development, the afore-described receiving and dispensing device for such additives which are to be added in a user-specific manner is arranged on the circle-arc-like end wall portion of the tub and is consequently connected directly upstream of the drum opening. On account of the preferably circular development of the breakthrough in the front wall, access to the end wall portion of the tub and to the receiving and dispensing device arranged thereon is simple.

The receiving and dispensing device is set up in an expedient manner for the purpose of dispensing the received additive automatically into the drum. To this end, the receiving and dispensing device is realized, for example, as a storage space with a first flap into which powder or a tablet is filled from outside of the drum unit. The first flap has associated therewith on the inside of the end wall portion a second flap which defines the storage space on the inside, and which opens automatically inward toward the drum in a corresponding program step and consequently releases the powder or the tablet into the drum. As an alternative to this, the storage space of the receiving and dispensing device is coupled with a (liquid) feed line, liquid being supplied by means of the feed line in the corresponding program step and the constituent parts of the powder or of the tablet (gradually) leeching out into the drum.

For tilting the drum unit automatically, in an expedient realization the washing machine includes a tilt device. The tilt device, in this case, preferably comprises an electric motor (tilt drive) and a traction drive—in particular a chain drive or a toothed belt drive—for coupling with the drum unit so as to transmit power. As a result, it is possible to hinge the drum unit in a particularly rigid manner particularly in the loading and unloading position as well as in the remaining positions. In an advantageous manner, it is possible, by means of such a traction drive, when loading the drum unit, to prevent the drum unit deflecting into the interior of the housing and consequently away from the user such that operation of the washing machine is further simplified. In an alternative realization of the tilt device, the device includes transmission of power to the drum unit in a hydraulic or pneumatic manner.

Position sensors (e.g. limit switches or other switching contacts) or stops are preferably arranged in the housing for the wash position and, where applicable, for the spin position and/or for the loading and unloading position such that it is possible to adjust the drum unit precisely in a repeatable manner into the respective position. The position sensors are expediently coupled with a control unit of the tilt device so as to transmit signals. As an alternative to this, the control unit of the tilt device is set up for the purpose of tilting the drum unit into the respective position by means of controlling the electric motor in a time-dependent manner.

In particular, in the case where the drum unit is tilted into the vertical position for the spin cycle when the washing machine is operating, the washing machine comprises, in an advantageous realization, at least one support element, preferably several support elements, against which the drum unit abuts (in particular is supported) in the horizontal position without or with simply a very small degree of freedom of movement. This mean that in the wash and/or spin cycle (carried out in the horizontal position) the drum unit is supported in a comparatively rigid manner on the housing. As only negligible vibrations of the drum unit caused by imbalance occur in the wash and/or rinse cycle due to the regularly low speeds of the drum, these can be simply diverted by means of the respective support element (where applicable, slightly damped, for example by means of an elastomer attachment). Consequently, in an advantageous manner, costly flexible (and damping) suspensions of the drum unit (known from conventional front loader washing machines) are able to be omitted.

In a further expedient realization, the washing machine includes a central control unit which is set up and provided for automatically controlling a wash program sequence and in particular the movement sequences of the drum and the drum unit. The control unit comprises, in particular, an interface for a touch-sensitive screen which serves for indicating wash program options and information and for inputting control instructions (e.g. for selecting predefined wash program sequences and/or for launching a wash program sequence). In an expedient variant, the control unit has associated therewith fixedly at the factory (and consequently constantly coupled via the interface) such a touch-sensitive screen. In an alternative variant, the interface is set up for coupling with a multimedia device, in particular a smartphone and/or tablet computer, on which in each case control software which is specifically associated with the washing machine is installed (“washing machine app”). The interface is realized in this case, for example, for physical coupling with the multimedia device as a USB interface (or a comparable type of connection) or for wireless communication by means of Bluetooth, WLAN and/or NFC (near field communication). In the latter case, information concerning the sequence of the wash program can be called up in a particularly user-friendly manner even from varying distances away from the washing machine and/or a wash program sequence can be launched. The control unit is set up and provided in particular for automatically executing the method according to the invention for operating the washing machine. In this case, the control unit can be realized within the framework of the invention as a non-programmable electronic circuit. The control unit is preferably formed, however, by a microcontroller in which the functionality for executing the method according to the invention for operating the washing machine is implemented in the form of a software module.

In an expedient variant of the method for operating the washing machine, the wash and/or rinse cycle is carried out first of all with the drum unit in the horizontal position and the drum unit is then tilted into the vertical position for the spin cycle. In this case, prior to or during the tilting into the vertical position, a measured variable which is characteristic of the imbalance of the rotating drum is acquired. In addition, the speed of the drum is varied (reduced or increased) expediently in dependence on the measured variable. Due to the variation in speed, the position of the items of laundry abutting against the drum wall is shifted such that a (gradual) reduction in the imbalance is achieved. As soon as a sufficiently low imbalance is determined by way of the measured variable—for example by way of exceeding the threshold value—the control unit concludes that the items of laundry are distributed in an (almost) uniform manner over the circumference of the drum wall and abruptly increases the speed of the drum. Due to the centrifugal force increased thereby, the items of laundry are “fixed” in their position against the inside wall of the drum. The drum unit is then tilted into the vertical position (whilst maintaining the speed). As an alternative to this, the drum unit is tilted into the vertical position whilst raising the speed further (i.e. increasing it further). The spin cycle can then be carried out with a particularly small amount of vibrations that are not caused by imbalance.

Characteristic means here and below that the measured variable includes quantitative information concerning the size of the imbalance such that the imbalance can be clearly read from the measured variable. The measured variable, in this connection, can provide the size of the imbalance directly. However, the measured variable can also be a variable which is directly or indirectly proportional to the imbalance to be indicated. In addition, the measured variable can also be related to the imbalance to be indicated in a non-linear, for example a logarithmic, exponential or polynomial (therefore quadratic, cubic, etc.) manner. The measured variable is preferably a motor characteristic of an electric motor driving the drum (designated as “drum motor”), for example the motor current, voltage or speed thereof. As an alternative to this, the washing machine includes one or several imbalance sensors, the signals of which are used as measured variables.

The term “exceeding the threshold value” is always to be understood here and below as directionally independent in the sense that the difference between the measured variable (or the temporal change thereof) and the threshold value changes the sign. Depending on the definition of the measured variable, the exceeding of the threshold value can be positive (in the sense of a real overshoot where the measured variable is greater than the threshold value) or negative (in the sense of a lower deviation where the measured variable is smaller than the threshold or limit value).

In a further expedient realization, the washing machine (in particular the control unit) is set up for executing additional, laundry-specific wash programs (i.e. matching the nature of the items of laundry to be washed). Thus, in particular in the case of the realization of the washing machine where the wash cycle is effected with the drum unit in the horizontal position, as an option there is a specific (wool) wash program sequence for laundry items made of wool (or another delicate material) where, after the launch, the drum unit is not tilted into the horizontal position for the wash cycle, but into the vertical position. In addition, there is also a shoe wash program sequence as an option where the wash cycle is effected with the drum unit in either the vertical or oblique position. In the latter case, therefore, the drum unit remains in the loading and unloading position for the wash cycle or, where applicable, is tilted back into the loading and unloading position once the drum cover has been automatically fitted. In a further optional wash program sequence, the drum unit is tilted about the tilt axis during the wash cycle such that the laundry items are moved in a particularly vigorous manner inside the drum.

Other features which are considered as characteristic for the invention are set forth in the appended claims.

Although the invention is illustrated and described herein as embodied in a washing machine and method for operating a washing machine, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.

The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 shows a schematic sectional representation of a side view of a washing machine, the washing machine comprising a housing and a drum unit which is arranged in the housing and is arranged in a loading and unloading position,

FIG. 2 shows a view according to FIG. 1 of the washing machine, the housing and the drum unit being open for loading and unloading,

FIG. 3 shows a view according to FIG. 1 of the washing machine, the drum unit being arranged in a wash position,

FIG. 4 shows a view according to FIG. 1 of the washing machine, the drum unit being arranged in a spin position,

FIG. 5 shows a view according to FIG. 3 of a further exemplary embodiment of the washing machine,

FIG. 6 shows a view according to FIG. 4 once again of a further exemplary embodiment of the washing machine,

FIG. 7 shows a view according to FIG. 2 of the washing machine according to FIG. 6,

FIG. 8 shows a view according to FIG. 2 of an alternative exemplary embodiment of the washing machine,

FIG. 9 shows a view according to FIG. 3 of the washing machine according to FIG. 8,

FIG. 10 shows a view according to FIG. 4 of the washing machine according to FIG. 8,

FIG. 11 shows a view according to FIG. 3 of a further exemplary embodiment of the washing machine and

FIG. 12 shows a view according to FIG. 3 once again of a further exemplary embodiment of the washing machine.

Parts which correspond to one another are always provided with identical references in all the figures.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, there is shown a schematic sectional representation of a washing machine 1. The washing machine 1 includes a housing 2 and drum unit 3. The drum unit 3 comprises a cup-like tub 4 and a cylindrical drum 5. The drum 5 is mounted in the tub 4 so as to be rotatable about a cylinder axis (designated below as drum axis 6). On one of its end faces, the tub 4 comprises a tub opening 7 and the drum 5 comprises a drum opening 8. The tub opening 7 and the drum opening 8 overlap at least in part and in this case form a loading and unloading opening 9 of the drum unit 3. This latter serves for loading and unloading items of laundry into or out of the drum 5. The drum unit 3 is additionally hinged in the housing so as to be tiltable about a tilt axis 10.

When the washing machine is operating, the tub 4 receives water or the so-called “washing liquid” (a mixture of water and additives, in the majority of cases detergent). In its lateral surface, the drum 5 comprises breakthroughs which are not shown in any detail and through which the washing liquid or the water passes into the interior of the drum 5 and wets the laundry items arranged there. Driven by a drum motor 11, when operating the drum 5 rotates about the drum axis 6 and, as a result, moves the laundry items on the drum wall—in particular on ribs 12 which project inward from the drum wall—through the washing liquid or the water.

In order to prevent the washing liquid or the water passing out of the tub 4 into the interior 13 of the housing 2 when the drum rotates, when operating the drum unit 3 is closed in a liquid-tight manner by means of a drum cover 14. The drum cover 14, in this case, is developed in such a manner that in addition to sealing the tub opening 7, it also covers a separating gap 15 which is formed between the edges of the tub opening 7 and the drum opening 8. The separating gap 15 is necessary in order to enable the drum 5 to rotate freely in the tub 4. Consequently, the drum cover 14 also prevents laundry items passing into the separating gap 15 and at the same time becoming damaged or being lost.

The drum cover 14 is hinged on an end face wall portion 16 of the tub 4 so as to be pivotable, as can be seen from FIG. 2. The end wall portion 16 covers the drum opening 8 from the top surface of the housing approximately in the form of a segment of a quarter circle, such that the loading and unloading opening 9 comprises the form of a flattened circle, in particular a segment of a three-quarter circle.

The housing 2 comprises a rounded front wall 20 at the front which is adapted to the tilt radius of the drum unit 3. The front wall 20 includes a circular breakthrough 21 which covers the loading and unloading opening 9 of the drum unit 3 with the drum unit 3 in the position shown. For opening and closing the breakthrough 21, the housing 2 includes a sliding door 22 which is displaceable in a guide rail (not shown in any detail) from the closed position 23 shown in FIG. 1 in the direction of the bottom surface of the housing 2 into an open position 24 shown in FIG. 2 The sliding door 22 comprises a transparent windowpane (not shown in any detail) through which the user is able to look into the interior 13, in particular onto the drum unit 3. In the exemplary embodiment shown, the sliding door 22 is manually displaceable and comprises a handle 25 for this purpose. In an alternative exemplary embodiment which is not shown, the washing machine 1 comprises a door drive for opening and closing the sliding door 22 automatically.

The washing machine 1 additionally includes a control unit 30 which is realized as a means for controlling the sequences for different predefined and specifically user-programmable wash program sequences. For indicating and selecting predefined wash program sequences and for inputting (programming) the user-specific wash programs, the control unit 30 includes a touch-sensitive screen 31. In an exemplary embodiment that is not shown, the screen 31 is not realized as part of the control unit 30, but rather the control unit 30 includes an interface for physical or cable-free coupling with a smartphone and/or a tablet computer or another computer, on which in each case control software (for example an application) which is matched specifically to the washing machine 1 is implemented.

For dosing the additives (in particular detergent and/or fabric softener) to the washing liquid, the washing machine 1 includes a (main) dosing unit 35. This latter is arranged in a base region 36 of the housing 2 and comprises one or several storage containers for receiving a stock of solid, powdery and/or liquid additives. Under instruction from the control unit 30 (i.e. in dependence on the chosen wash program sequence), the dosing unit 35 doses a specifically predefined amount of additive to the washing liquid from the respective storage container. This is dispensed into the tub 4 by means of a pump 37.

In addition, the washing machine 1 includes a receiving and dispensing device 38 for user-specific additives which are to be dosed and/or added independently by the user (for example for certain laundry materials such as silk etc.). The receiving and dispensing device 38 is arranged in the end wall portion 16 of the tub 4. The receiving and dispensing device 38 includes two flaps which open on both sides of the end wall portion 16 and close a storage space. The additives are filled into the storage space from the outside by the user. The inner flap is set up for the purpose of releasing the additives inward into the drum 5 during the operation of the washing machine 1 at a signal from the control unit 30.

If the washing machine 1 is inoperative, the drum unit 3 is arranged in a loading and unloading position 40. In the loading and unloading position 40, the drum unit 3 is tilted in such a manner about a tilt axis 10 that the drum axis 6 points obliquely upward, here at a 45-degree angle. As a result, the loading and unloading opening 9 of the drum unit 3 also points obliquely upward and the loading and unloading of the drum 5 is made particularly easier for the user. In order to prevent laundry items or, where applicable, liquid dripping from the laundry items, passing into the interior 13 when loading and unloading, the washing machine 1 includes a bellows 41. The bellows 41 is arranged running around the breakthrough 21 on the inside surface of the front wall 20 and is adjustable in its length between the front wall 20 and the drum unit 3 automatically by means of a drive (not shown in any detail). In the loading and unloading position 40, the bellows 41 is extended and is “docked” in a liquid-tight manner on the end face of the drum unit 3 (therefore on the tub 4) (see FIGS. 1 and 2). The bellows 41 is additionally coupled with an outlet line (not shown in any detail) by means of which liquid dripping onto the bellows 41 is supplied to the wastewater system of the washing machine 1 and is consequently conducted out of the housing 2.

For loading the drum 5, the user slides the sliding door 22 into its open position 24 and by touching a button opens the drum cover 14 which, as a result, automatically pivots (for example driven by a spring mechanism) into its open position shown in FIG. 2. After loading, the user closes the drum cover 14 manually, where applicable fills an additive into the receiving and dispensing device 38 and closes the sliding door 22. The user then chooses the desired wash program sequence on the screen 31 and launches the same.

Once the wash program sequence has been launched, in a first operating state the drum unit 3 is tilted out of the loading and unloading position 40 into a wash position (shown in FIG. 3), in which the drum axis 6 is aligned in a horizontal manner. The wash position is designated below as the horizontal position 42. The tilting of the drum unit 3 is effected by means of a tilt device 43 which is shown in FIG. 5 and described below. The wash cycle, and where applicable a rinse cycle, take place with the drum unit 3 in the horizontal position 42. In this case, washing liquid (clear water in the rinse cycle) is introduced into the tub 4 by means of the pump 37. The drum 5 rotates in the meantime at a comparatively slow speed with repeated direction reversal. As a result, the laundry items are wetted with the washing liquid and are moved back and forth vigorously in the washing liquid for washing out the impurities. In the rinse cycle that follows where applicable, the washing liquid is replaced by clear water and consequently detergent residues are rinsed out of the laundry items.

In order to reduce the quantity of liquid absorbed in the laundry items following the wash and or rinse cycle, following the first operating state then comes a second operating state in which the drum 5 rotates at a higher speed and the liquid is expelled out of the laundry items by centrifugal forces (designated below as a spin cycle). For the spin cycle the drum unit 3 is tilted into a spin position in which the drum axis 6 is aligned in a vertical manner (designated below as the vertical position 44). The vertical position 44 of the drum unit 3 is shown in FIG. 4. The advantage here is that with the drum 5 vertically upright, the effect of vibrations in the spin cycle caused by imbalance is chiefly radially to the drum axis 6 and only in a negligible manner along the direction of the drum axis 6.

In order to make it possible for the laundry items to be distributed in as uniform a manner as possible over the inside wall of the drum 5 and consequently for as small as possible an imbalance of the drum 5 in the spin cycle, a characteristic measured variable for the imbalance of the drum 5, for example the motor current of the drum motor 11, is acquired by the control unit 30 between the wash or rinse cycle and the spin cycle (i.e. before the drum unit 3 is tilted from the horizontal position 42 into the vertical position 44) with the drum 5 rotating. In addition, in this case, (in dependence on the measured variable) the speed of the drum 5 is varied. As a result of varying the speed, the position of the laundry items abutting against the inside wall is able to be shifted. If a sufficiently low imbalance of the drum 5 is determined, in particular by way of the measured variable exceeding a threshold value, the control unit 30 increases the speed of the drum 5 abruptly. As a result, due to the centrifugal force the laundry items are pressed against the inside wall of the drum 5 and are consequently fixed in their position. The drum unit 3 is then tilted into the vertical position 44 and the speed of the drum 5 is increased further to the spin speed provided for the spin cycle.

Once the spin cycle has been completed, the drum unit 3 is automatically tipped back into the loading and unloading position.

In an alternative wash program sequence, for example for shoes, it can be provided within the framework of the invention that the drum unit 3 remains in the loading and unloading position 40 for the wash cycle. In a further wash program sequence for delicate textiles (for example wool, silk or the like) it can also be provided in addition that the wash cycle is effected with the drum unit 3 in the vertical position.

FIG. 5 shows an optional exemplary embodiment of the washing machine 1. The washing machine 1, in this connection, includes two indicator plates 50 which are fastened to the outside wall of the tub 50. The indicator plates are part of an indicator device which serves for the purpose of giving the user information concerning the operating state of the washing machine 1. The indicator plates 50 are fastened in such a manner that through the windowpane in the sliding door 22 one of the indicator plates 50 is visible in the horizontal position 42 and the other indicator plate 50 is visible in the vertical position 44. For example, the indicator plates carry inscriptions such as “spin cycle” or “wash cycle” or are realized as an alternative to this as electronic displays (for example LCDs) which indicate the remaining running time of the respective wash, rinse or spin cycle.

FIG. 5 additionally shows the tilt device 43 which includes an electric motor 55 and a chain drive 56 for transmitting power to the drum unit 3. As a result, the tilt device 43 is designed in a comparatively rigid manner such that vibrating or flexing of the drum unit 3 is reduced in particular in the loading and unloading position 40. In addition, the washing machine 1 also includes support elements 60, against which the drum unit 3 is tipped and supported in the horizontal position 42. The support elements 60 comprise a damping layer produced from elastomer. Consequently, the freedom of movement of the drum unit 3 is extensively restricted in the horizontal position 42. As the spin cycle is effected at a high drum speed with the drum 5 in the vertical position 44, in the horizontal position 42 only negligible vibrations of the drum unit 3 occur which hardly have to be cushioned. Consequently, comparatively costly suspension and damping can be omitted and the simply developed support elements 60 used instead.

FIGS. 6 and 7 show a further alternative exemplary embodiment of the washing machine 1. In the case of the exemplary embodiment, the drum cover 14 is not hinged so as to be pivotable on the end wall portion 16 but is completely separable from the drum unit 3. To this end, the washing machine 1 includes a device designated as a park device 62 which comprises a link guide 63, by means of which the drum cover 14, with the drum unit 3 arranged in the vertical position 44, is lifted from the drum unit and placed into a receiving mean 64. In the receiving means 64, the drum cover is arranged in a park position 65 which is shown in FIG. 6. The (open) drum unit 3 is then tilted into the loading and unloading position 40.

In a correspondingly reversed manner, at the start of a wash program sequence the drum unit 3 is first of all tipped into the vertical position 44 and the drum cover 14 is placed in position and locked by the park device 62. The drum unit 3 is then tilted into the corresponding position (i.e. in particular into the horizontal position 42.

FIGS. 8 to 10 show a further, alternative exemplary embodiment of the washing machine 1. In this connection, the dosing unit 35 and the pump 37 are not shown for the purposes of a simplified representation. The dosing unit 35 is arranged as an option on the top surface of the housing 2 in the case of the exemplary embodiment.

The front wall 20 is developed so as to be movable in the manner of a louvre (or blind) in the exemplary embodiment according to FIGS. 8 to 10 and is coupled with the drum unit 3 so as to move uniformly with the drum unit. Consequently, the breakthrough 21 of the front wall 20 always remains in alignment with the loading and unloading opening 9 of the drum unit 3. Depending on the direction of movement, the front wall 20 is rolled-up on a roller 70 arranged in each case on the top surface of the housing 2 and in the base region 36 of the housing 2 or is unrolled from the roller. For closing both the breakthrough 21 of the front wall 20 and the loading and unloading opening 9, the washing machine 1 comprises a loading door 71. The loading door is realized in such a manner that it bridges both the spacing between the front wall 20 and the drum unit 3, and bridges the separating gap 15 between the drum 5 and the tub 4 (see FIGS. 9 and 10). The loading and unloading opening 9 is realized in a circular manner in the exemplary embodiment. The bellows 41 is not realized so as to be length-adjustable but is constantly coupled with the front wall 20 and the drum unit 3.

FIG. 11 shows a further exemplary embodiment of the washing machine 1. In this exemplary embodiment also the front wall 20 is developed so as to be movable and is coupled with the drum unit 3 for movement with the drum unit. The front wall 20, in this case, is formed from several lamellae 72 which are located transversely to the direction of movement of the drum unit 3 and which slide over one another on the top surface or in the bottom region 36 of the housing 2 when the drum unit 3 tilts.

FIG. 12 once again shows a further exemplary embodiment of the washing machine 1. The displaceable (movable) front wall 20, in this case, is realized in a substantially rigid manner. I.e. the front wall 20 is realized as a type of arched front plate which slides along a guide in the base region 36 into the housing 2 when the drum unit 3 is tilted into the wash position 42 and in a corresponding manner exits from the housing 2 on the top surface of the housing. In order to keep the extent of the front wall 20, which is approximately in the shape of a segment of a circle with reference to the tilt axis 10, as small as possible and consequently to achieve as short as possible a plunge distance of the front wall 20 in the base region 36 of the housing 2, a diaphragm 73 (a housing projection) is arranged on the housing in the base region 36 (shown in a sectional view in FIG. 12). The diaphragm 73 covers the loading door 71 in part with the drum unit 3 in the wash position 42. A comparable diaphragm 74 is arranged on the top surface of the housing 2. As a result, the front wall 20 can cover less than a quarter circle above and below the breakthrough 21 such that only a small installation space needs to be kept free in the housing 2 for receiving the plunging portion of the front wall 20. Access protection 75, for example a comparatively rigid brush seal or a rubber lip, is arranged on the housing 2 on both diaphragms 72 and 74 as anti-pinch protection.

The object of the invention is not restricted to the afore-described exemplary embodiments. Rather, further embodiments of the invention are able to be deduced by the expert from the preceding description. In particular, the individual features of the invention described by way of the different exemplary embodiments and their development variants can also be combined together in another manner.

The following is a summary list of reference numerals and the corresponding structure used in the above description of the invention:

-   -   1 Washing machine     -   2 Housing     -   3 Drum unit     -   4 Tub     -   5 Drum     -   6 Drum axis     -   7 Tub opening     -   8 Drum opening     -   9 Loading and unloading opening     -   10 Tilt axis     -   11 Drum motor     -   12 Rib     -   13 Interior     -   14 Drum cover     -   15 Separating gap     -   16 End wall portion     -   20 Front wall     -   21 Breakthrough     -   22 Sliding door     -   23 Closed position     -   24 Open position     -   30 Control unit     -   31 Screen     -   35 Dosing unit     -   36 Base region     -   37 Pump     -   38 Receiving and dispensing device     -   40 Loading and unloading position     -   41 Bellows     -   42 Horizontal position     -   43 Tilt device     -   44 Vertical position     -   50 Indicator plate     -   55 Electric motor     -   56 Chain drive     -   60 Support element     -   62 Park device     -   63 Link guide     -   64 Receiving means     -   65 Park position     -   70 Roller     -   71 Loading door     -   72 Lamella     -   73 Diaphragm     -   74 Diaphragm     -   75 Access protection 

1. A washing machine, comprising: a housing; a drum unit mounted in said housing, said drum unit including a cup-shaped tub and a cylindrical drum with a cylinder axis, wherein said drum is rotatably mounted in said tub about said cylinder axis; said tub and said drum opening out at an end face in a loading and unloading opening of said drum unit; said drum unit being disposed to assume a loading and unloading position wherein said loading and unloading opening points obliquely upward; said drum unit being mounted in said housing for tilting in a wash cycle relative to the loading and unloading position about a tilt axis that extends perpendicular to said cylinder axis of said drum, into a wash position; and said housing having a displaceable front wall coupled with said drum unit, said front wall being formed with a breakthrough that covers said loading and unloading opening of said drum unit, and a door articulated on said front wall for closing both said breakthrough and said loading and unloading opening.
 2. The washing machine according to claim 1, wherein said drum unit is tilted in the wash position to align said cylinder axis of said drum horizontally.
 3. The washing machine according to claim 2, wherein said drum unit is tilted into a spin position in a spin cycle with said cylinder axis of said drum aligned vertically.
 4. The washing machine according to claim 2, wherein said drum unit is tilted in an additional wash position to align said cylinder axis of said drum vertically or obliquely.
 5. The washing machine according to claim 1, which comprises a bellows arranged between said drum unit and said front wall, said bellows being configured to bridge a spacing between said front wall and said drum unit and to close the spacing liquid-tight.
 6. The washing machine according to claim 1, which comprises at least one support element, wherein said drum element, with said cylinder axis of said drum aligned horizontally, abuts against said at least one support element without a degree of freedom of movement.
 7. The washing machine according to claim 1, which comprises at least one support element, wherein said drum element, with said cylinder axis of said drum aligned horizontally, abuts against said at least one support element with a small degree of freedom of movement.
 8. The washing machine according to claim 1, which comprises: a control unit for automatic sequential control of a sequence of a wash program, said control unit being configured for: tilting said drum unit from the wash position, with said cylinder axis of said drum aligned horizontally, into a spin position, with said cylinder axis aligned vertically, for a spin cycle; acquiring a measured variable which is characteristic of an imbalance of the rotating drum prior to or during the tilting; varying a speed of said drum such that a position of items of laundry located in said drum is changed and an amount of the imbalance is reduced; and when the imbalance is sufficiently low, increasing the speed abruptly and tilting the drum unit into the spin position while maintaining or increasing the speed further.
 9. A method for operating a washing machine, the method comprising: providing a washing machine according to claim 1; upon a launch of a wash program sequence, tilting the drum unit in the wash cycle from the loading and unloading position into the wash position; and at an end of the wash program sequence, tilting the drum unit into the loading and unloading position.
 10. The method according to claim 9, which comprises: tilting the drum unit from the wash position, with the cylinder axis of the drum aligned horizontally, for a spin cycle into a spin position, with the cylinder axis of the drum aligned vertically; prior to, or during the tilting, acquiring a measured variable which is characteristic of an imbalance of the rotating drum; if necessary, varying a speed of the drum to change a position of items of laundry in the drum and to reduce the imbalance; and abruptly increasing the speed of the drum when the imbalance is sufficiently low and tilting the drum unit into the spin position while maintaining or increasing the speed further. 